It is well known that many light bulbs are used and require regular replacement. In most cases light bulbs are sold to the general public in pairs packaged in a sleeve with the bulb end of one bulb exposed at one end of the sleeve and the bulb end of the other exposed at the other end of the sleeve and the two smaller diameter base ends in overlapping relationship adjacent the centre of the sleeve.
To protect the bulbs and cushion them such sleeves are normally formed from a single face material, i.e. laminate of a liner and a corrugated medium with the corrugations projecting inward and with the longitudinal axis of the corrugations extending substantially circumferentially of the sleeve to resist axial movement of the bulbs from the sleeve. Usually a small flute size such as an E-flute is used to form the corrugations in the medium. Spacing between the wall of the tube is normally designed for the size bulb to be packaged so that the corrugations are compressed slightly by the bulb end of the light bulbs when they are inserted in the sleeve.
In a conventional lamp wrapper the partition used to separate the two bulbs extends at an angle across the tubular member from one side wall to an adjacent side wall and from a corner adjacent to one axial end of the sleeve towards a diagonally opposite corner adjacent to the other axial end of the sleeve. The partition for forming this partition is made from material that extends from the manufacturer's joint forming flap and which is severed and provided with a diagonal fold line connecting the partition panel to the manufacturer's joint forming flap. In some sleeves a second fold line substantially perpendicular to the fold line connecting the partition to the manufacturer's joint forming flap will extend from one end of the diagonal fold line to provide a flap that rests against the adjacent side wall when the lamp wrapper tube is erected and aids in positioning the partition to extend diagonally across the sleeve from one corner towards the diagonally opposite corner.
It will be apparent that the partition of the prior art provides ample protection for the light bulbs but also requires a significant amount of extra material over and above that necessary to form the sleeve itself since the partition panel is in fact an extension of the manufacturer's joint forming flap. Obviously in forming blanks for producing these lamp wrappers and partition panels of one blank may overlap with another thereby reducing the total board requirements however, even with full overlap extra board equivalent to about half of the width of the partition panel at least is necessary for each wrapper.
Considering that millions of such wrappers blanks are used annually, the extra board required to form the lamp wrappers cumulatively amounts to a significant cost.